Introduction: Scar deciduosis provides a research model that enables us to assess the impact of decidua on the activity and quality of the immune cells infiltrating this scar tissue. This unique model allows us to examine these processes under conditions excluding the impact of placental cells which, along with decidual cells, control the activity of immune cells under physiological conditions. RCAS1 is a protein responsible for the suppression of the cytotoxic immune response during gestation. The present study evaluates the immunoreactivity level of RCAS1 with respect to immune cell status in the decidua and scar deciduosis.
Material and methods: Immunohistochemical analysis of RCAS1, CD3, CD56, CD25, and CD69 antigen immunoreactivity levels was performed in tissue samples derived from scar deciduosis that developed after a previous cesarean section and were excised during a subsequent cesarean section. The control group consisted of decidua samples derived from cesarean section at term.
Results: A statistically significantly higher RCAS1 immunoreactivity level was identified in scar deciduosis tissue samples than in decidua derived from a cesarean section at term. The number of CD56+ cells and immunoreactivity of the CD25 antigen level were observed to be statistically significantly higher in scar deciduosis than in the control group.
Conclusion: The presence of an enhanced number of immune cells of higher activity in ectopic decidua during the final step of decidualization seems to be associated with an increase in the immunoreactivity level of RCAS1.